import java.util.Scanner;

public class Test20230808_6 {
    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        int flag=0;
        int a = scanner.nextInt();
        for(int i=2; i<a; i++) {
        if(a%i == 0){
               flag=1;
               break;
            }
        }
        if(flag==0){
            System.out.println(a+"是素数");
        }
        else
            System.out.println(a+"不是素数");
    }
}
